# Add file sha256 in 405.GetInfo.0.2.uavcan

**URL:** <https://forum.opencyphal.org/t/add-file-sha256-in-405-getinfo-0-2-uavcan/1462>\
**Category:** Development & Maintenance\
**Created:** [September 27, 2021, 12:28pm UTC](https://forum.opencyphal.org/t/add-file-sha256-in-405-getinfo-0-2-uavcan/1462 "2021-09-27T12:28:06Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Cherish-forever](https://forum.opencyphal.org/user_avatar/forum.opencyphal.org/cherish-forever/32/802_2.png) [@Cherish-forever](https://forum.opencyphal.org/u/Cherish-forever)\
**Post date:** [September 27, 2021, 12:28pm UTC](https://forum.opencyphal.org/t/add-file-sha256-in-405-getinfo-0-2-uavcan/1462/1 "2021-09-27T12:28:06Z")

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I think add file sha256 to GetInfo response will be better.  
so that it can be verified after firmware has been download.  
crc64 in file name is out of fashion.

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**Author:** ![pavel.kirienko](https://forum.opencyphal.org/user_avatar/forum.opencyphal.org/pavel.kirienko/32/9_2.png) [@pavel.kirienko](https://forum.opencyphal.org/u/pavel.kirienko)\
**Post date:** [September 27, 2021, 1:38pm UTC](https://forum.opencyphal.org/t/add-file-sha256-in-405-getinfo-0-2-uavcan/1462/2 "2021-09-27T13:38:03Z")

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This might be challenging to implement because SHA-256 may be too slow to compute for a large file to keep up with the timing constraints imposed by the service call. We used to have a CRC field in the v0 counterpart of this service that was removed for the same reason.

The preferred alternative is to keep the hash in a separate file, which is common practice with FTP servers on the Internet:

> <https://github.com/UAVCAN/public_regulated_data_types/blob/b02e6899a319ddefbab41b820d167c95dd00174d/uavcan/file/408.Read.1.1.uavcan#L13-L28>

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**Author:** ![Cherish-forever](https://forum.opencyphal.org/user_avatar/forum.opencyphal.org/cherish-forever/32/802_2.png) [@Cherish-forever](https://forum.opencyphal.org/u/Cherish-forever)\
**Post date:** [September 28, 2021, 5:59am UTC](https://forum.opencyphal.org/t/add-file-sha256-in-405-getinfo-0-2-uavcan/1462/3 "2021-09-28T05:59:53Z")

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Thank you very much, very professional